Forestry Commission Bulletin 123 Managing Rides, Roadsides and Edge Habitats in Lowland Forests Richard Ferris and Clive Carter Forestry Commission ARCHIVE FORESTRY COMMISSION BULLETIN 123 Managing Rides, Roadsides and Edge Habitats in Lowland Forests Richard Ferris1 and Clive Carter2 Woodland, Ecology Branch, 2form erly Entomology Branch, Forest Research, Alice Holt Lodge, Wrecclesham, Farnham, Surrey GU10 4LH Edinburgh: Forestry Commission © Crown copyright 2000 Applications for reproduction should be made to HMSO, The Copyright Unit, St Clements House, 2-16 Colegate, Norwich NR3 1BQ ISBN 0 85538 415 8 Ferris, R.; Carter, C. 2000 Managing Rides, Roadsides and Edge Habitats in Lowland Forests. Bulletin 123. Forestry Commission, Edinburgh, xxii + 86 FDC 267:907.1:18:15: (410) KEYWORDS: Conservation, Forestry, Rides, Roadsides, Edges, Open areas, Succession, Vegetation management Acknowledgements The authors would like to thank the many people in Forest Enterprise who have shared their experience of managing edges and open areas, particularly staff of Northants, South-East England, and The New Forest Districts. Thanks are also due to Fred Currie, Wildlife and Conservation Officer, Forestry Commission (England), for comments on an earlier draft of the Bulletin; Jenny Claridge for editing and overseeing the project through to completion; John Williams and George Gate for producing the artwork; and The Royal Greenwich Observatory for developing ideas about light modelling. The original project was conceived by Mark Anderson, and his role and that of Peter Buckley (Wye College, University of London) in making this Bulletin possible is gratefully acknowledged. Front cover: Sunlit forest edge with Enquiries relating to this publication high floristic diversity, Bentley Wood, should be addressed to: Wiltshire, (c .i.c a r t e r ) inset Silver-washed The Research Communications Officer fritillary, Argynnis paphia. ( c .i .c a r t e r ) Forest Research Alice Holt Lodge Back cover: A sunny rideside bay in a Wrecclesham, Famham Corsican pine plantation, Pembrey Surrey GU10 4LH Forest, Dyfed. ( r f e r r is ) left inset Ride mowing in a lowland beechwood, Micheldever, Hampshire, c r f e r r is ) right inset Primrose (Pnmula vulgaris), a woodland plant and important food source for the Duke of Burgundy fritillary (Hamearis lucina) which may benefit from ride or roadside man- agement. ( r .f e iir is ) Contents Page Acknowledgements ii List of plates v List of figures vii Summary ix Resume x Zusammenfassung xi Crynodeb xii 1 Introduction 1 Part One Ecology of Edges and Open Areas 3 2 Ecological value of woodland edges 5 Edges and open areas in traditionally managed woodlands 6 Edge habitats and open ground in plantation forests 6 3 Light and microclimate 8 Solar radiation 8 The microclimate of edges 8 Aspect, slope and latitude 8 4 Vegetation succession 17 Ecological principles 17 Regeneration 17 Impact of herbivores 22 Field and ground vegetation 24 5 Animals in woodland edges and open areas 27 Invertebrates 27 Birds 31 Mammals 34 Reptiles and amphibians 35 Part Two The Management of Edges 37 6 Deciding on a management strategy 39 7 Design principles 42 The visual impact of edges 42 Using site and stand variation to enhance diversity 42 Roads and rides 43 8 Vegetation management 46 Creating vegetation zones 46 Managing grass and herb vegetation 49 Short turf and bare ground 50 Tools and techniques 52 9 Monitoring changes in plant and animal communities 58 Vegetation monitoring 58 Assessment of bird populations 60 Small mammals 60 Supporting information 62 References 63 Appendix 1 Scientific names for animal species in text 70 Appendix 2 Scientific names for plant species in text 73 iv List of plates Plates 1-27 between pages 36 and 37. 1 A shaded woodland ride, Straits Inclosure, Alice Holt Forest, Surrey/Hampshire. 2 Managed coppice: many plants and animals in British woodlands have become adapted to the regular disturbance and open ground conditions created by coppicing. 3 A well-established ride in ancient semi-natural woodland, Wakerley Great Wood, Northamptonshire. 4 Wet, implanted areas can provide valuable wildlife habitats within forests: Bentley Wood, Wiltshire. 5 Timber loading bays provide valuable temporary open space: Alice Holt Forest, Surrey/Hampshire. 6 Powerline corridors require management of regenerating scrub and can provide permanent networks of open ground within forests: Haldon Forest, Devon. 7 Marsh fritillary, Eurodryas aurinia. This butterfly utilises damp unimproved meadows and boggy hollows, and is one of our most rapidly declining species. 8 The pearl-bordered fritillary, Boloria euphrosyne, breeds in woodland clearings or unimproved grassland habitats with scattered scrub or abundant bracken. It is the subject of a species Action Plan as part of the UK Biodiversity Action Plan. 9a Black knapweed, Centaurea nigra, a valuable nectar source for butterflies, found in open grassland habitats with forests. 9b Common dog-violet, Viola riviniana is an important food plant for fritillary butterflies. 10 A newly created forest ride cut into a pole-stage beech plantation, Black Wood, Micheldever, Hampshire. 11 Vegetation succession in a six-year old forest ride in Black Wood, Micheldever, Hampshire. 12 A fenced exclosure plot in a forest ride in Black Wood, Micheldever, Hampshire, showing the impact of browsing by deer and rabbits on woody regeneration along the forest edge. 13 A well-developed shrubby edge along the perimeter of a forest ride in Firestone Copse, Isle of Wight. 14 Open grassy habitat alongside a widened forest ride in Dodsley Wood, Hampshire. 15 Ringlet, Aphantopus hyperantus, a local but fairly common butterfly in much of England, Wales, Ireland and southern Scotland. v 16 Ride or road intersections may be utilised to create large glades or box- junctions by cutting off the comers of adjacent compartments: Oakley Wood, Bemwood Forest, Oxfordshire. 17 A widened ride managed for pheasants, Phasianus colchicus. 18 Common dormouse, Muscardinus avellanarius. Arboreal ‘bridges’ of hazel, Corylus aveUana, can help provide crossing points in rides. 19 The retention of large, old trees alongside forest edges and open areas is important for wildlife, where this does not conflict with safety considerations. Most woodland bats in Britain use large, old trees as roost sites. 20 Sand lizard, Lacerta agilis. Patches of bare ground along ridesides and roadsides on heathland sites provide valuable basking areas. 21,22, Ride-widening operations at Bushey Leaze, Hampshire. Narrow, shaded 23 rides may be enhanced by cutting back edge trees to create open conditions. 24 Ride mowing using a tractor and swipe at Black Wood, Micheldever, Hampshire. 25 Cutting invasive scrub using a tractor-mounted long-reach flail cutter at Pembrey Forest, Dyfed. 26 A cyclic system for managing rideside vegetation: linear coppice strips and box-junctions cut on eight-year rotation. 27 Forage harvesters may be used to cut and collect vegetation on sites where build-up of nutrients may pose a threat to floristic diversity. vi List of figures 1.1 Important milestones in the development of sustainable forest management and biodiversity conservation as key objectives in UK forestry. 3.1 Simultaneous air temperature measurements made with shielded thermometers at ground level and 1 m above the ground, in sun and shade, in a 9 m wide E-W oriented forest ride at Holt Pound, Alice Holt Forest, Hampshire on (a) 21 June 1992 and (b) 21 December 1992. 3.2 Hours of sunlight maps for rideside bays 24 m x 50 m, oriented (a) E-W and Cb) N-S, surrounded by trees 15 m tall on 22 June for a latitude of N51° 30'. 3.3 Graphs showing (a) maximum hours of sunlight and (b) heat energy for a central point in a hypothetical ride system, widened to equal the height of the trees, for a latitude of N51° 30' at Micheldever Forest, Hampshire. 3.4 The effects of removing rows of edge trees (a) from the north edge and (b) from the south edge on the extent of direct sunlight or shade received on a forest ride or road. 3.5 A ride system for which tree height exceeds ride width on a south-facing slope, under which conditions north-south rides receive greater heat energy as a result of illumination at the middle of the day. East-west rides will accumulate a greater total of sunshine hours from morning and evening illumination, but with less heating power due to lower sun angles. 3.6 The influence of latitude on the relative altitudes of the sun and the tree crop, and hence illumination of the forest floor at woodland edges. 3.7 Asouth-facing road, or rideside bay, showing the ‘hotspots’ on south-facing banks where the radiation flux is greatest for the period around midday. These may be particularly valuable as reptile basking areas. 4.1 (a)-(f): Model for the successional development of vegetation at forest edges. 4.2 Mean seedling heights of regenerating trees and shrubs on a newly created ride edge, five years after cutting back of the tree canopy, showing the impact of protection from herbivore browsing using fenced exclosures, Micheldever Forest, Hampshire (P31-35 beech). 5.1 Butterfly responses to ride management in a P31-36 beech plantation 1986-1991, Micheldever Forest, Hampshire. 5.2 Cutting regimes for box junctions at forest road or ride intersections. 7.1 View of an idealised external forest edge showing irregularly spaced and sized groups and individual trees and shrubs, which provide visual and ecological diversity, with a more stable longer-term structure. 7.2 The creation of large comer glades or box-junctions at the intersections of forest rides or roads by the removal of edge trees. Visual diversity may be enhanced or improved by the creation of asymmetric glades rather than even-sized segments. 8.1 A simple two-zone cutting system, suitable for forest rides not managed specifically for wildlife.